One of the most controversial things about Apple’s iPhone is the looming question of software support. Apple has touted iPhone’s Mac OS X core, and the ability to run Widgets, Java-based Google Maps, and several Mac OS X-based applications.

However, Apple has not answered as to what, if any, software users will be able to add to their five-month-away smart device. Read more for the breakdown, and of course, what you think of the Apple app limbo.

Here’s what we do know:

Apple has constantly noted in Widget design to prepare for the widget to not exist on the Mac. While Widgets can carry Mac OS X code, it is promoted that developers rely on JavaScript, XML, and raw images. Because of this, it is likely that Widgets using non-Mac code will run on iPhone.

We also know that the Home screen is designed to have more apps. Looking at the iPhone screen shows a lot of blank space for items. These items could be future Apple applications, but it appears to allow for at least some level of user addition. Never would Apple have wasted so much screen-space otherwise.

Also, Google Maps is a J2ME application. Because J2ME is permitted by Cingular on all their devices, it is unlikely there is any objection from installing, at the very least, J2ME MIDP 2.0 applications. Full Java is not defined yet… we don’t know if the unit will allow for J2ME MDP or J2SE.

This of course, leaves the ability to run native Mac applications. This is something that is in debate. Engadget analysts claim that the iPhone will be completely locked down… which for the reasons above is suspect. With no SDK however, there is certainly doubt in the minds of many if this is indeed a smartphone.

The root cause here may be data pricing. Apple would prefer Cingular to bill the device as a consumer device with $19.99/month data instead of the $44.99/month price for data-centric devices. Most data-centric devices are considered as such because they run native code, such as Palm OS or Windows Mobile.

Symbian devices however are treated as consumer devices… giving Apple potential wiggle-room to run native OSX-condensed applications on the device without digging into users for data charges.